It has been common in the prior art to utilize rotating, supporting, insulating column structures to effect the operation of load-break disconnecting switch structures. For example, note U.S. Pat. Nos. 2,911,506 -- Owens, 2,853,584 -- Upton, Jr., 2,769,063 -- Lingal, and 2,737,556 -- MacNeill et al.
As far as we are aware, in prior-art devices separate insulator columns were required for both operation and tripping. An example of such a device is set forth in U.S. Pat. No. 3,116,391 -- Lindell et al.